Stabilized vinyl resin



Patented Dec. 30, 1941 urn 2,207,771 s'rsnmzsn vmxnnssm Victor Yngse, Lakewood, Ohio, assignor to Carbide and Carbon Chemicals Corporation, a corporation of New York No Drawing. Application June as, 1938, serial No. 215,411

e Claims. (01. zoo-s5) The invention relates to stabilized vinyl resins and compositions contalnlngthe same. It is particularly concerned with newand improved stabilizing materials which show definite advanpounding and processing of such resinsinto molded and extruded articles, or as constituents 01' certain coating compositions it is usually necessary to subject the plastics to certain degrees of heat. Under such conditions, as well as atel'e vated temperatures which may benencountered terials in vinyl resin plastics which may be contacted with sulfur compounds.

A quite broad class of these alkyl and aryl lead and tin oxides and hydroxides have shown a very satisfactory stabilizing action. Among the compounds having an alkyl group those are .especially preferred which contain in the alkyl radical three or more carbon atoms, as included in the propyl; isopropyl, butyl, isobutyl, tertiary butyl, the various amyl groups, and the like. As aryl derivatives those containing phenyl, tolyl, xylyl and naphthyl groups are typical. A mixed hydrocarbon grouping in either the oxide or bydroxide compound is also appropriate, which may includetwo or more difierent alkyl radicals in a the molecule or mixed aryl and alkyl groups.

in normal usage, a tendency toward deteriora- 1 tion is quite commonly encountered. To prevent decomposition in this respect it has, therefore, been considered essential with known types of vinyl resin to incorporate therewith additive ma- Representative specific compounds especially effective in their stabilizing action are the followterlals adapted to exert a stabilizing action, and

numerous compounds have been suggested for this purpose.

Improvements afforded by this invention are especially applicable to vinyl resins-of the type produced by the more or less completcl lymerization of a vinyl halidas'uch as vinyl chloride, or by the conjoint polymerization oi mixtures of vinyl halides with vinyl esters of aliphatic acids. Resins oi the lsttei -typcaredescz lbed in U. S. Patent 1,935,577 to E. W. Reid, and anidng these, the conjcintly polymerized product of vinyl chloride and vinyl acetate containing about 60% to 95% oi vinyl chloride in the polymer, and having an average molecular. weight of Irom about 5,000 to 20,000, as estimated from the w clflc viscosity of dilute solutions according to Staudingcfs method, is especially susceptibletp stabilization by the compounds hereinafter described.

In accordance with my invention I have found that orsano-metallic compounds of lead and tin, particularly the oxides and hydroxides of alkyl and aryl derivatives oi these metals will function- Triphenyl tin hydroxide-" (CsHshSnOH Dlphenyl tin oxide (CsHshSnO Propyl diphenyl tin hyv droxide (CaH'z) (CsHrDsSnOI-I Dlphenyl lead oxide (CeH5)2PbO Triphenyl lead hydroxide (CsH5)'3PbOH Propyl diphenyl lead bydroxide (CsHq) (CsHs) zPbOH Tributyl tin hydroxide (C4Hs)3SnOI-I Dibutyl tin oxide (Cd-1925110 'iibutyl lead hydroxlde (cinnamon Dibutyl lead oxide '(ClH MPbO as excellent stabilizers ior vinyl resins, and when intimately dispersed therein will provide plastic compositions of substantially improved resistance to heat deterioration. A particular sdven tage in these compounds, other than their actual stabilizing function, also resides in the fact it. I

that resin compositions incorporating them show practically no tendency toward'discoloratlon in the presence or hydrogen sulfide, thereby presenting .an especially valuable application of the ma All of the above and related compounds are intended to be included within the broader scope oi the invention, and within the classification which may be defined as organo-metalllc lead and tin oxides and hydroxides, that is, organometallic compounds in whichthe inorganic constituent is of the group consisting of lead and tin radicals in combination with oxide and hydroxide radicals. The stabilizing compounds previouslydescribed may be designated broadly by the formula (R1) 13MB) where R1 is a radical of the group oi alkyl and aryl, M is atetravalent metal 0! the group of tin and lead, R is one oi the group of oxygen and hydroxyl, a: ls'an integer from 2 to 3, :1: being 2when R is oxygen and .1: being 3 when R is hydroxyl.

53 vinyl chloride in the polymer, and having an average molecular weight of from about 8,000 to 12,000. The triphenyl tin hydroxide, in quantities about 1.0% by weight of'tlie resin, was intimately and thoroughly dispersed in the resinous mass by milling on a heated two roll mill. In subsequent processing at elevated temperatures the plastic remained clear, and under heat tests at 135' C. the resistance to deterioration as evidenced by discoloring or blackening oi the resin was very good.

Using a polymerized vinyl resin similar to that in the above example, a lacquer composition was made upcontaining varying proportions, from about 1% to by weight of the resin, of triphenxy tin hydroxide as a stabilizer. Clear solutions oi the stabilized resin were sprayed in thin films onto steel panels and the coated panels baked at various temperatures. Films containing from 2% to 5% concentration of the triphenyl tin hydroxide showed no apparent decomposition when baked for 30 minutes at a temperature of 350 F., whereas a film of similar resin, but without the stabilizer, blackened and decomposed entirely in 5 minutes under the same conditions.

Further tests employing other organo-metallic oxides and hydroxides 01 lead and tin showed results comparative to the above examples; and

in all instances heat stability of the vinyl resin plastic was appreciably improved over compositions of the same resin component but with prior known stabilizing materials.

bility are also within a range heretofore found suitable with other materials, varying from about 03% t5 asthma by weight "or the'viny'l' resin; In the compounding of plastic compositions for various uses, there may be included any of the common solvents, plasticizers, pigments, and other modifying materials without detrimental eiiect upon the heat stability aiiorded by these new stabilizers.

Modifications within the scope of theappended claims will be evident and are intended to be included within the invention as defined therein. This application is a continuation-in-part of my copending application Serial No. 118,568,

flled December 31, 1936, now Patent No. 2,219,463.

-I claim:

dispersed therein, said stabilizing material comprising about 0.5% to 5.0% by weight of the resin 0! triphenyl tin hydroxide.

2. A heat-stable vinyl resin composition including polymerized vinyl halide, said composition containing intimately dispersed therein a stabilizing material'comprising an organo-metallic compound in which the inorganic constiradicals in combination with oxygen and hydroxyl radicals.

3. A heat-stable vinyl resin composition including polymerized vinyl halide, said composition containingintimately dispersed therein a stabilizing material comprising a member of the group designated by the formula (R1) =M(R) where R1 is a radical of the group of alkyl and aryl, M is a tetravalent metal of the group of tin and lead,

it is one of the group of oxygen and hydroxyl, .r I

isanintegerirom2to 3,:nbcing2whenRis oxygen and :2 being 3 when R is hydroxyl.

4. A heat-stable resinous composition comprising a vinyl resin substantially identical with that formed by the conjoint polymerization of a.vinyl -is an integer from 2 to 3, :n being 2 when R is oxygen and 3 being 3 when R is hydroxyl.

5. Process for producing heat-stable resinous compositions which comprises intimately mixing a vinyl resin including polymerized vinyl halide with a stabilizing material comprising an organokmetallic compound in which the inorganic constituent is'oi the group consisting of lead and tin radicals in combination with oxygen and hydroxyl radicals.

6. Process for producing heat-stable resinous compositions which comprises intimately mixing a vinyl resin substantially identical with that formed by the conjoint polymerization of vinyl chloride with vinyl acetate and containing in the polymer about 60% to 95% vinyl chloride with a stabilizing material comprising a member 1. A heat-stable resinous composition comprising a vinyl resin substantially identical with that formed by the conjoint polymerization of vinyl chloride with vinyl acetate and containing in the polymer about to of vinyl chloride, and a stabilizing material intimately oi the group designated .by the formula (R1)=M(R) where R1 is a radicalof the group of alkyl and aryl, M is a tetravalent metal of the group of tin and lead, R is one of the group of 55 oxygen and lrydroxyl, .1: is an integerirom 2 to 3, 1 being 2 whenR is oxygen and .1: being 3 when R is hydronl.

, VICTOR YNGVE.

tuent is of the group consisting of lead and tin CERTIFICATE OF CORRECTION. Patent No. 2,267,777. December 0, 19in.

VICTOR YNGVE.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, second column, line 51 for "Tibntyl" read Tributy1--; page 2, first column, line 15, for "phenxy" read --phenyl--; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 10th dayof February, A. D. 19h2.

Henry Van Arsdale, (Seal) Acting Commissioner of Patents. 

